Tel Aviv  - Israel's Defence Ministry said Thursday it was keeping the crossing points into the Gaza Strip shut again for the day, in response to three rockets fired from the salient on Tuesday which violated a fragile truce with Palestinian militants.

Major Peter Lerner said an "ongoing assessment" was taking place as to whether the crossings would reopen on Friday.

Israeli Defence Minister Ehud Barak decided to close the crossings on Wednesday after the rocket attacks on southern Israel.

Hamas, the main Palestinian militant group, said the Israeli move was in itself a violation of the ceasefire.

The truce went into effect at 0300 GMT on June 19, and is supposed to end months of violence between the sides.

It calls on the militants to cease their almost-daily rocket launches at southern Israeli towns and villages, and on Israel to stop launching air raids on, and ground raids in, the Gaza Strip.

Israel has also undertaken to ease its blockade of the enclave, but the pace depends on negotiations for the release of an Israeli soldier held captive in the Strip for the past two years.

Israel imposed the blockade in response to the rocket and mortar attacks from the salient at its southern towns and villages. It had further tightened the stranglehold after Hamas seized sole control of the enclave in June last year.

The Islamic Jihad claimed responsibility for the rocket launches Tuesday, saying they were in retaliation for Israel killing a senior Jihad militant and his roommate in the West Bank city of Nablus earlier in the day.

The West Bank is not covered by the Egyptian-brokered ceasefire. (dpa)